You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 

73 lines
2.7 KiB

// David Eberly, Geometric Tools, Redmond WA 98052
// Copyright (c) 1998-2021
// Distributed under the Boost Software License, Version 1.0.
// https://www.boost.org/LICENSE_1_0.txt
// https://www.geometrictools.com/License/Boost/LICENSE_1_0.txt
// Version: 4.0.2019.08.13
#pragma once
#include <Mathematics/DistPointTriangle.h>
#include <Mathematics/Tetrahedron3.h>
namespace gte
{
template <typename Real>
class DCPQuery<Real, Vector3<Real>, Tetrahedron3<Real>>
{
public:
struct Result
{
Real distance, sqrDistance;
Vector3<Real> tetrahedronClosestPoint;
};
Result operator()(Vector3<Real> const& point, Tetrahedron3<Real> const& tetrahedron)
{
Result result;
// Construct the planes for the faces of the tetrahedron. The
// normals are outer pointing, but specified not to be unit
// length. We only need to know sidedness of the query point,
// so we will save cycles by not computing unit-length normals.
Plane3<Real> planes[4];
tetrahedron.GetPlanes(planes);
// Determine which faces are visible to the query point. Only
// these need to be processed by point-to-triangle distance
// queries.
result.sqrDistance = std::numeric_limits<Real>::max();
result.tetrahedronClosestPoint = Vector3<Real>::Zero();
for (int i = 0; i < 4; ++i)
{
if (Dot(planes[i].normal, point) >= planes[i].constant)
{
int indices[3] = { 0, 0, 0 };
tetrahedron.GetFaceIndices(i, indices);
Triangle3<Real> triangle(
tetrahedron.v[indices[0]],
tetrahedron.v[indices[1]],
tetrahedron.v[indices[2]]);
DCPQuery<Real, Vector3<Real>, Triangle3<Real>> query;
auto ptResult = query(point, triangle);
if (ptResult.sqrDistance < result.sqrDistance)
{
result.sqrDistance = ptResult.sqrDistance;
result.tetrahedronClosestPoint = ptResult.closest;
}
}
}
if (result.sqrDistance == std::numeric_limits<Real>::max())
{
// The query point is inside the solid tetrahedron. Report a
// zero distance. The closest points are identical.
result.sqrDistance = (Real)0;
result.tetrahedronClosestPoint = point;
}
result.distance = std::sqrt(result.sqrDistance);
return result;
}
};
}